Abstract The business organization operates in an environment and though its interactions with the various elements of this environment, it justifies its existence. The customers is the essence of business. The business organization is expected to continually to satisfy it customer hence this work gets out to investigate the factors affecting the improved customer service department in the commercial bank with particular reference to Union bank if Nigeria Plc. The method applied in this study is a combination of content analysis and survey research the data were sources through both primary and secondary sources. The unit of analysis Union bank of Nigeria plc Garden Avenue branch and the major find of this research work including that the dissatisfaction experience by customers is due to the inefficiency of the bank staff there is a relationship between improved service delivery and bank efficiency and bank profitability. The limitation encountered further studies should be carried out to service between two banks operating with the country.